Associations between the stages of change and the pros and cons of smoking in a longitudinal study of Swiss smokers.

To develop effective smoking prevention interventions, we need to identify modifiable variables, such as the "pros and cons" of smoking, that predict self-initiated smoking cessation. Our objective was to assess associations between the pros and cons of smoking and the stages of change, both cross-sectionally and longitudinally, in a cohort of smokers. In cross-sectional comparisons, the pros of smoking were 0.19-0.31 standard deviation (SD) higher and the cons 0.79-0.87 SD lower in the precontemplation than in the preparation stage. In follow-up data, progressing from precontemplation to contemplation and from contemplation to preparation was associated with substantial and significant increases in the cons (+0.71 SD and +0.50 SD, respectively). No longitudinal associations were found between changes in pros of smoking and progress through stages. Thus this study added evidence from longitudinal data to published evidence from cross-sectional data about the association between the cons of smoking and the stages of change. Intervention studies are necessary to establish whether this association is causal.